1. Field
The present invention disclosed herein relates to a system and method for measuring quality of a multimedia service of a packet network.
2. Description of the Related Art
In order to provide a service in a packet network, multimedia data such as voice data and image data are IP (Internet Protocol)-packetized to be transmitted through the Internet by using a residential access network such as an xDSL network and cable network constructed for providing an Internet service or an enterprise access network through a dedicated line. The packet network service such as the VoIP (Voice over Internet Protocol) service was originally used for a voice call via an IP network which is a data communication packet network, but is currently used for providing a multimedia service including not only a voice but also an image.
The VoIP, which provides the multimedia service by using the packet network such as the Internet, is limited in terms of quality due to bandwidth limitation and packet loss of the Internet.
That is, since IP-packetized multimedia data (voice data and image data) share network resources with typical data flowing through the Internet, data loss, the excessive transmission delay, or the non-sequential and irregular packet arrival may occur when congestion of the typical data occurs or when network quality is degraded. Particularly, since an RTP (Real-time Transport Protocol) packet is loaded not on a TCP (Transmission Control Protocol) with connectivity but on a UDP (User Datagram Protocol) with non-connectivity so as to be transmitted, excessive packet loss may easily occur. Therefore, in order to secure the quality of the multimedia such as the voice call, the VoIP service using the Internet is required to transmit the multimedia data more in real time in comparison with typical data transmission which requires integrity. Accordingly, due to limitation of the Internet with respect to real time transmission, quality degradation has become an important issue.
A VoIP service provider needs to continuously measure and analyze the multimedia quality in order to secure valid multimedia quality for a service user, thereby preventing the multimedia quality degradation and satisfying the user.
Particularly, since the VoIP service uses a floating line unlike a PSTN (Public Switched Telephone Network) which uses a dedicated line, considerable packet loss and delay may highly possibly occur according to the Internet traffic. Therefore, quality of service (QoS) of the VoIP service is inferior to that of the PSTN. Accordingly, it is strongly required to correctly measure the multimedia quality.
To this end, various Korean Patent Applications, e.g., Korean Patent Application Laid-open Publication No. 2007-0060861, propose various technologies for measuring the multimedia quality in the VoIP service network.
However, according to typical devices for measuring the multimedia quality in the VoIP network, a probe is installed on a location being subjected to measurement in order to collect data, or an empty port of a hub such as a switch or router of a network device is used as a mirroring port in order to collect data. That is, the VoIP network quality is manually measured. Thus, additional measuring equipment, which costs high, is required.
Further, the additional measuring equipment should be always carried, and an additional linkage function should be implemented in order to transmit the measurement result to an external server. Further, a terminal for measuring the quality of the multimedia data including the voice and image data is not provided. Moreover, when the quality is degraded, a troubled section cannot be detected.